Compass



Oct. 6, 1942- F. e. EUBANKS COMPASS Filed Nov. 28, 1940 2 Sheets-Sheet 1 Am G fwzz/yw,

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Oct. 6, 1942.

'F. e. EUBANKS 2,297,999

COMPASS Filed NOV. 28, 1940 2 Sheets-Sheet 2 ayflwi M-MW ATTOQ/YEK Patented Qfct. 6, 194-2 COMPASS Floyd G. Eubanks; Pasadena, Calif., assignor of forty-seven and one-half per cent to Francis E. Vaughan, Pasadena, Calif., and five per cent to Robert M. McManigal, Compton, Calif.

Application November 28, 1940, SerialNo. 367,644

5 Claims.

My invention relates to new and usefulimprovements in compasses.

For the purpose of illustration I disclose a compass comprising two legs whose upper ends are pivoted on a grooved cylindrical member against which they are held by a C-shaped spring, a screw pivoted to said legs and-functioning to control the distance between the lower ends of said legs, and screw clamps at the lower ends of said legs for holding metal points, pencil leads, pens or other accessories. A small handle at the upper end of the compass serves as a convenient means for manipulating it.

The object of my invention is to provide a compass leg which can be constructed of complementary stampings which are identical throughout most stages of their manufacture.

Another object of my inventionis to provide a compass of lightweight in orderto facilitate the drawing of small circles.

Another object of my invention is to provide a compass in which there is no lost motion'between the component parts in order to insure great accuracy in the drawing of circles.

Another object of my invention is to so construct each leg of the compass that it holds the cylindrical nut between the component parts of the leg under a light spring pressure in order to eliminate all end play on the part of the cylindrical nut in the leg. This is a very important feature in that the elimination of lost motion renders possible the drawing of very small circles and insures great accuracy in the drawing of large circles.

Another object of my invention is to provide a compass which is economical to construct and which is efiicient in operation.

My invention has many other objects which will be apparent from a study of the following specification read in connection with the accompanying drawings.

Referring to the drawings:

Figure 1 is an upright front View of the compass.

Figure 2 is an upright side view showing the open truss construction of the legs.

Figure 3 is a plan View of one of the stampings from which the legs are built.

Figure 4 is a side view of the stamping shown in Figure 3.

Figure 5 is a plan of a stamping completed as half of a leg.

Figure 6 is a side View of the half leg shown in Figure 5.

Figure '7 is a section along the line 'l1'in Figure 5.

Figure S'is a plan ofa stamping completed as the half of a leg complementary tothe half shown in Figure 5;

Figure 9 is a side view of the half leg shown in Figure 8. V

Figure 10 is a section along the line Ill-l0 in Figure 8.

Figure 11 is a side view showing the stamping shown in Figure 6 welded to the'stamping shown in Figure 9.

Figure 12is a section along the line l2l2 of Figure 11.

Referring to said drawings, the numeral I lindicates a grooved hinge pin which carries the upper ends of the legs [2 and [3, said legs being held in the grooves of the hinge pin II by the C-shaped spring I4. The constructionof the legs l2 and I3 is a very important feature of my invention and will be described indetail hereinafter. I prefer to describe my entire compass now in-order to show clearlythe structural environment of said legs. A handle I5 is pressed on the shaft l6. which passes through a hole in the spring Hi and is firmly screwed into the hinge pin II.

A center-screw IT can be turned'by' means of 'a thumb-piece I8. The screw threads inll are left-handed on one side of the thumb-piece l8 and right-handed on the other. The centerscrew l! is articulated with the legs I2 and I3 by means of the cylindrical nuts 19 andEB, respectively. Each of these cylindrical nuts l9 and 20 fits smoothly in holes 23 in the two halves of the corresponding leg. Transverse holes through the nuts I9 and 20 are threaded to receive the centerscrew ll. In passing through each of the nuts the center-screw IT at the same time passes between the two halves ofthe corresponding leg. The halves of each leg have some spring to them, and the spacing between'the halves is so gauged that they bear lightly against the center-screw and thereby eliminate all end play on the part of said cylindrical nuts in the legs. The lower end of each leg is provided with a clamp operated by a, screw 2| which can be used to hold either a pencil lead, a steel point, the tang of a suitably designed open so that circles may be drawn in ink, or the tang of some other accessory.

The construction of one of the compass legs is shown in Figures 3, 4, 5, 6, '7, 8, 9, 10, 11 and 12. Figures 3 and 4 show one of the four identical stampings from which the legs of the compass are constructed. In Figures 3 to 12, 22 is a hole to receive the clamp screw 2|; 23 is a hole to receive one of the cylindrical nuts l9 and 20; 24 is a recess to admit the thumb piece l8 when the legs l2 and I3 are brought together; 25 is a recess to receive the hinge pin I; 26 is a recess to receive the ends of the C-spring I4.

Figures 5, 6 and 7 show one of the stampings completed as half of a leg. In these figures, the hole 22 has been threaded to receive the threaded part of the thumb screw 2|; 2! is a groove to receive a pencil, steel point, or tang of a pen or other acceszory; 28 is a strong punch mark represented by an indentation on the upper side of the stamping and by a boss projecting from the lower side.

Figures 8, 9 and 10 show one of the stampings completed as the complementary half of the leg. In these figures, the hole 29 has been drilled out to clear the threaded part of the thumb screw 2|; 30 is a groove to receiv a pencil, steel point, or tang of a pen or other accessory; 3| is a strong punch mark represented by a boss projecting above the upper side of the stamping and by an indentation on the lower side.

In Figures 11 and 12 the stampings shown in Figures 6 and 9 have been resistance welded together at the bosses 28 and 3|. The grooves 21 and 30 now form, in effect, a hole to receive a pencil lead, steel point, or tang of a pen, or other accessory. By tightening th screw 2!, the grooved ends of the two halves can be brought together to clamp upon the object introduced between grooves 21 and 3D. The upper ends of the two halves are spread apart to receive the cylindrical nuts 19 and 20 through which passes the center screw l1, shown in Figures 1 and 2.

The other leg is constructed in precisely the same manner from stampings identical to those shown in Figures and 8.

In Figures 5 and 8 are the two halves whose recesses 25 are received in the grooves in the hinge pin II. The two halves of the other leg are similarly received by the grooves in the hinge pin 1 I. The two legs are held upon the hinge pin II by the C-spling I4 whose ends are received by the notches 26 in the legs. These notches are placed a short distance above the axis of the hinge pin H so that the C-spring tends to bring the upper ends of the legs l2 and [3 together and thus spread apart the lower ends of said legs. The actual spread of the lower ends of the legs is controlled by the center-screw ll.

One of the advantages of my compass is that the legs can be constructed easily and accurately. The legs of other precision compasses are laboriously machined from heavy stock whereas the four leg halves of my compass are stamped from sheet stock, a simple and accurate operation.

Another advantage is the halves of each leg can be made sufiiciently thin to have some spring in them.

Another advantage is that the legs have less metal in them and are therefore of lighter weight than other instruments of the same size and material.

Other advantages and the use and operation of the compass of my invention will be readily understood by those skilled in the art to which the invention appertains. While I have described the form of my invention which I now consider to be the best embodiment thereof, I desire to have it understood that the form shown is merely illustrative and that the invention is not to be limited to the details disclosed herein, but is to be accorded the full scope of the appended claims.

I claim:

1. A compass comprising a pair of legs, a hinge pin, an adjustment screw, each of said legs embracing a pair of complementary sheet stampings spaced at their upper ends, said stampings converging and being secured together below the adjusting screw, and a spring member arranged to'urge the upper ends of said legs together and to retain said stampings in engagement with said hinge pin.

2. A compass comprising a pair of legs, a hinge pin having spaced grooves thereon, an adjustment screw, each of said legs embracing a pair of complementary sheet stampings spaced at their upper ends by engagement with said spaced grooves on said hinge pin, said stampings converging and being secured together adjacent their lower ends, and a spring member arranged to urge the upper ends of said legs together and to retain said stampings in engagement with said spaced grooves on said hinge pin.

3. A compass comprising a pair of legs, a hinge pin, an adjustment screw, one of said legs embracing a pair of complementary sheet stampings spaced at their upper ends, said stampings converging and being secured below said adjustment screw to thus provide an open truss construction, and complementary holes intermediate the ends of said stampings engaging and supporting between said stampings a member coacting with said adjustment screw for controlling the spread of said legs.

4. A compass comprising a pair of legs, a hinge pin, and an adjustment screw, one of said legs embracing a pair of complementary sheet stampings spaced at their upper ends and converging and being secured below said adjustment screw to thus provide an open truss construction, said stampings being shaped intermediate their ends to receive and resiliently engage therebetween a member coacting with said adjustment screw for controlling the spread of said legs.

5. A compass leg comprising a pair of complementary members secured together adjacent their lower ends, said members diverging outwardly and being secured in spaced relationship at their upper ends to thereby provide a lightweight open truss construction of high rigidity.

FLOYD G. EUBANKS. 

